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Psychometrika

, Volume 34, Issue 4, pp 489–507 | Cite as

Estimation of true score and error variance for tests under various equivalence assumptions

  • Walter Kristof
Article

Abstract

Maximum-likelihood estimators of true score variance and error variance for mental tests are derived for six different models of equivalent measurements. Statistical properties of the estimators are examined. Main emphasis is placed upon essentiallyτ-equivalent measurements. A statistical criterion for this type of measurement is given. The solution of the comparatively simple maximum-likelihood equations is effected by means of a rapid Newton-Raphson procedure. Two different initial estimators are considered and their relative merits in terms of second moments evaluated. Four numerical examples are appended by way of illustration.

Keywords

Public Policy Statistical Criterion Statistical Theory Error Variance Relative Merit 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Psychometric Society 1969

Authors and Affiliations

  • Walter Kristof
    • 1
  1. 1.Educational Testing ServiceUSA

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